Several techniques are available for characterizing the surface microstructure of smooth components. Often it is necessary to compare the results from two or more of these techniques. This can lead to problems unless it is understood that all measurement techniques are bandwidth limited, and each technique has a characteristic transfer function. We will discuss several techniques in this regard, including the optical profilometer (WYKO), the optical scatterometer (both angle-resolved and TIS), and the mechanical profilometer (Talystep). A number of samples having different microstructure properties were characterized using these techniques, and results will be discussed.